Mossberg FLEX Stock Model 500/590 Standard Medium Synthetic Shotgun Accessory

The Mossberg FLEX Stock is a modular synthetic replacement stock built for shooters who want to dial in their Mossberg 500 or 590 shotgun to their exact build and body type. This standard medium stock features a 13-1/2-inch length of pull and an integrated recoil pad, giving you a ready-to-shoot setup that absorbs felt recoil without adding weight. Synthetic construction means it'll handle hard use, weather, and bumps in and out of the truck without cracking or warping.

What sets the FLEX system apart is the tool-less locking mechanism—swap stocks or adjust your setup in the field without carrying a wrench or screwdriver. That means faster transitions between hunting scenarios, quicker modifications if you're sharing the gun with other shooters, or simple maintenance without a trip to the bench. If you've already invested in a Mossberg 500 or 590 and want to customize the ergonomics or improve the handling, the FLEX stock is a direct upgrade that actually works.

The standard medium length is designed to work well for most shooters running a conventional or tactical setup. Whether you're hunting waterfowl, upland game, or running a home-defense shotgun, a properly fitted stock makes the gun point naturally and reduces fatigue during long days in the field.

Key Features

• Tool-less locking system for quick stock swaps and field adjustments
• Integrated recoil pad absorbs felt recoil
• Durable synthetic material resists weather and abuse
• 13-1/2-inch length of pull fits standard to medium-frame shooters
• Drop-in compatibility with Mossberg 500 and 590 platforms

Specifications

Frequently Asked Questions

What Mossberg shotguns is this stock compatible with?

The FLEX stock works with Mossberg FLEX 500 and 590 shotguns only. Do not attempt to install on other models or brands.

Can I change the stock without tools?

Yes. The tool-less locking system lets you swap or adjust the stock in the field or at home with your hands—no wrenches, screwdrivers, or specialized tools required.

Is this a good fit for a standard-sized shooter?

The standard medium stock with a 13-1/2-inch length of pull is designed for most conventional shooters. If you're significantly smaller or larger, or have a very long or short arm length, confirm fit before purchasing.

What's included in the box?

You receive the FLEX stock with integrated recoil pad. Installation onto a compatible Mossberg 500 or 590 requires no additional parts.